1. Field of the Invention
The present invention relates to a liquid discharge head for discharging a liquid and, more particularly, to an ink jet recording head for recording by discharging ink onto a recording medium (medium to be recorded). The invention can be applied to: an apparatus for recording to a recording medium, that is, an apparatus such as printer, copying apparatus, facsimile apparatus having a communication system, word processor having a printer unit, or the like; and further, an industrial recording apparatus complexly combined with the various kinds of processing apparatuses.
2. Description of the Related Art
In the related art, a liquid discharge recording apparatus for recording by discharging recording liquid (ink) from discharge ports of a liquid discharge head has been known as a recording apparatus which is excellent in terms of low noises, high speed recording, and the like.
As a liquid discharge recording method, various methods have been proposed so far and there are a liquid discharge recording method which has been improved and put as a product on the market and a liquid discharge recording method to which a supreme effort for putting into practical use is being made.
For example, as illustrated in FIGS. 1A and 1B, such a kind of liquid discharge head is constructed by an element substrate 10 and a liquid containing member 70 made of a resin. The element substrate 10 has: an orifice plate 40 having discharge ports 30 for discharging the ink; a flow path 50 communicated with each discharge port 30; energy generating elements 20 each of which constructs a part of the flow path 50 and generates an energy for discharging; and a supply port 60 for supplying the liquid to each flow path 50. The liquid containing member 70 made of the resin has a communication port 80 communicated with each supply port 60.
In the head having such a construction as mentioned above, as disclosed in U.S. Pat. No. 5,013,383, there has been known such a technique that the element substrate 10 formed with the orifice plate 40 and the supply ports 60 is directly adhered to the liquid containing member 70 made of the resin by using a mounting adhesive agent 110. At this time, since a surface roughness of an element substrate adhering surface of the liquid containing member 70 made of the resin is not always good, generally, the surface is often thickly coated with the mounting adhesive agent. A thermosetting adhesive agent of a single liquid type which can be easily handled is used. After that, electric wiring members 130 are adhered to the liquid containing member 70 made of the resin and an electric connection is performed by the electric wiring members 130 and the element substrates 10. After that, an ambience of the element substrates 10 is sealed by an ambient sealing material 90. Further, an electric joint portion of the electric wiring member 130 and the element substrate 10 is sealed by a lead sealing material 100.
In the liquid discharge head with the above construction, since the thermosetting adhesive agent is used to adhere the element substrate made of Si and the liquid containing member made of the resin, it is necessary to heat. By the heating, both of the element substrate made of Si and the liquid containing member made of the resin are thermally expanded and they are adhered with the adhesive agent in such an expanding state. However, since there is a difference between a coefficient of linear expansion of the element substrate made of Si and that of the liquid containing member made of the resin, when a temperature of the liquid containing member made of the resin is returned to an ordinary temperature after completion of the thermosetting, the liquid containing member made of the resin is contracted larger than the element substrate made of Si.
Although such a large contraction of the liquid containing member made of the resin has not been considered as a serious problem so far, it will become a problem if the element substrate made of Si is further microfabricated in order to further reduce the costs in the future. For example, as illustrated in FIG. 2A, there is a case where a stress is caused in the element substrate made of Si by the contraction of the liquid containing member made of the resin and the element substrate made of Si is deformed in a an arch shape so that a length of edge portion and a length of center portion differ. Thus, as illustrated in FIG. 2B showing a cross sectional view of the center portion in FIG. 2A, there is a possibility that the discharge ports, supply ports, orifice plate, and the like are deformed and a defective discharge of the liquid occurs.